je.st
news
Tag: number
Hurricane Sam Forecast Discussion Number 29
2021-09-29 22:51:15| National Hurricane Center (Atlantic)
Issued at 500 PM AST Wed Sep 29 2021 108 WTNT43 KNHC 292051 TCDAT3 Hurricane Sam Discussion Number 29 NWS National Hurricane Center Miami FL AL182021 500 PM AST Wed Sep 29 2021 Sam continues to exhibit a well-organized cloud pattern on satellite imagery, although there is some asymmetry of the coldest-topped convection around the center. The hurricane is also maintaining numerous banding features with well-defined upper-level anticyclonic outflow. Observations from an Air Force Hurricane Hunter plane showed peak 700 mb fight-level winds of 130 kt in the northeast quadrant which, using the standard reduction, corresponds to maximum surface winds of 117 kt. However, the maximum SFMR-observed surface winds were 103 kt. Based on these data, with more emphasis on the flight-level winds, the current intensity estimate is held at 115 kt. The aircraft also measured a minimum central pressure of 945 mb by dropsonde. Since the hurricane is forecast to remain in an environment of low vertical shear and to remain over warm waters through 48 hours, Sam could restrengthen a little more during the next day or so. Since the Hurricane Hunters reported a concentric eyewall, short-term strengthening may be curtailed until the eyewall replacement cycle completes. Later in the forecast period, gradual weakening is likely due to cooler SSTs and increasing shear. The official intensity forecast is in very good agreement with the latest corrected consensus prediction. Sam will likely be close to extratropical transition around day 5. The initial motion is still northwestward, or 310/8 kt. During the next few days, Sam is likely to move northwestward and then northward around the western periphery of a large subtropical high pressure system centered over the eastern Atlantic. A turn to the north-northeast and northeast is expected later in the forecast period as Sam begins to encounter the flow on the southern side of a large mid-tropospheric trough moving through Atlantic Canada. The track guidance models remain in excellent agreement through 72 hours, including the time that Sam passes by Bermuda. At days 4-5 there is some divergence of the model guidance, apparently due to how Sam may interact with the trough. Most notably the ECMWF is a lot slower than the other global models suggesting that the trough will at least partially bypass it in that case. Not much change has been made to the previous official forecast, however, and the NHC track remains very close to the TVCN dynamical model consensus. Key Messages: 1. Swells generated by Sam will impact the Lesser Antilles during the next several days. Swells are expected to reach Bermuda and the Bahamas in a day or so, and then spread to the United States east coast by this weekend. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 20.2N 57.6W 115 KT 130 MPH 12H 30/0600Z 21.2N 58.9W 120 KT 140 MPH 24H 30/1800Z 23.1N 60.4W 120 KT 140 MPH 36H 01/0600Z 25.6N 61.4W 120 KT 140 MPH 48H 01/1800Z 28.3N 61.9W 115 KT 130 MPH 60H 02/0600Z 31.0N 61.3W 110 KT 125 MPH 72H 02/1800Z 33.6N 59.9W 100 KT 115 MPH 96H 03/1800Z 37.5N 55.0W 85 KT 100 MPH 120H 04/1800Z 42.0N 48.5W 70 KT 80 MPH $$ Forecaster Pasch
Tags: number
discussion
sam
forecast
Hurricane Sam Public Advisory Number 29
2021-09-29 22:50:19| National Hurricane Center (Atlantic)
Issued at 500 PM AST Wed Sep 29 2021 000 WTNT33 KNHC 292050 TCPAT3 BULLETIN Hurricane Sam Advisory Number 29 NWS National Hurricane Center Miami FL AL182021 500 PM AST Wed Sep 29 2021 ...CATEGORY 4 HURRICANE SAM PASSING WELL TO THE EAST-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...20.2N 57.6W ABOUT 385 MI...620 KM ENE OF THE NORTHERN LEEWARD ISLANDS MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H PRESENT MOVEMENT...NW OR 310 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 500 PM AST (2100 UTC), the center of Hurricane Sam was located near latitude 20.2 North, longitude 57.6 West. Sam is moving toward the northwest near 9 mph (15 km/h), and this general motion with an increase in forward speed is expected during the next couple of days. A turn toward the north is forecast by Friday. On the forecast track, Sam will continue to pass well to the east-northeast of the northern Leeward Islands through tonight. Maximum sustained winds are near 130 mph (215 km/h) with higher gusts. Sam is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in intensity are expected during the next couple of days, but Sam is forecast to remain a major hurricane through late this week. Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km). An Air Force Reserve Unit Hurricane Hunter aircraft reported a minimum central pressure of 945 mb (27.91 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Sam can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC. SURF: Swells generated by Sam will impact the Lesser Antilles during the next several days. Swells are expected to reach Bermuda and the Bahamas in a day or so, and then spread to the United States east coast by this weekend. These swells could cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1100 PM AST. $$ Forecaster Pasch
Tags: number
public
sam
advisory
Hurricane Sam Wind Speed Probabilities Number 29
2021-09-29 22:50:19| National Hurricane Center (Atlantic)
Issued at 2100 UTC WED SEP 29 2021 000 FONT13 KNHC 292050 PWSAT3 HURRICANE SAM WIND SPEED PROBABILITIES NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182021 2100 UTC WED SEP 29 2021 AT 2100Z THE CENTER OF HURRICANE SAM WAS LOCATED NEAR LATITUDE 20.2 NORTH...LONGITUDE 57.6 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 115 KTS...130 MPH...215 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 18Z WED AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 18Z WED 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN PERIODS TO TO TO TO TO TO TO 06Z THU 18Z THU 06Z FRI 18Z FRI 18Z SAT 18Z SUN 18Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 X X( X) X( X) X( X) X( X) X( X) 7( 7) CAPE RACE NFLD 34 X X( X) X( X) X( X) X( X) X( X) 5( 5) BERMUDA 34 X X( X) X( X) 4( 4) 19(23) 1(24) 1(25) BERMUDA 50 X X( X) X( X) X( X) 4( 4) 1( 5) X( 5) BERMUDA 64 X X( X) X( X) X( X) 1( 1) X( 1) X( 1) $$ FORECASTER PASCH
Hurricane Sam Forecast Advisory Number 29
2021-09-29 22:49:55| National Hurricane Center (Atlantic)
Issued at 2100 UTC WED SEP 29 2021 000 WTNT23 KNHC 292049 TCMAT3 HURRICANE SAM FORECAST/ADVISORY NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL182021 2100 UTC WED SEP 29 2021 THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. HURRICANE CENTER LOCATED NEAR 20.2N 57.6W AT 29/2100Z POSITION ACCURATE WITHIN 15 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 945 MB MAX SUSTAINED WINDS 115 KT WITH GUSTS TO 140 KT. 64 KT....... 35NE 30SE 25SW 30NW. 50 KT....... 70NE 50SE 40SW 50NW. 34 KT.......120NE 120SE 80SW 90NW. 12 FT SEAS..180NE 120SE 150SW 180NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 20.2N 57.6W AT 29/2100Z AT 29/1800Z CENTER WAS LOCATED NEAR 19.8N 57.3W FORECAST VALID 30/0600Z 21.2N 58.9W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 35NE 30SE 25SW 30NW. 50 KT... 60NE 50SE 40SW 50NW. 34 KT...120NE 120SE 90SW 100NW. FORECAST VALID 30/1800Z 23.1N 60.4W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 35NE 30SE 25SW 30NW. 50 KT... 60NE 50SE 40SW 50NW. 34 KT...120NE 120SE 90SW 100NW. FORECAST VALID 01/0600Z 25.6N 61.4W MAX WIND 120 KT...GUSTS 145 KT. 64 KT... 40NE 40SE 30SW 40NW. 50 KT... 70NE 60SE 50SW 60NW. 34 KT...130NE 130SE 90SW 100NW. FORECAST VALID 01/1800Z 28.3N 61.9W MAX WIND 115 KT...GUSTS 140 KT. 64 KT... 50NE 40SE 30SW 40NW. 50 KT... 70NE 70SE 60SW 60NW. 34 KT...130NE 140SE 90SW 100NW. FORECAST VALID 02/0600Z 31.0N 61.3W MAX WIND 110 KT...GUSTS 135 KT. 50 KT... 70NE 70SE 60SW 60NW. 34 KT...140NE 150SE 110SW 120NW. FORECAST VALID 02/1800Z 33.6N 59.9W MAX WIND 100 KT...GUSTS 120 KT. 50 KT... 70NE 70SE 60SW 60NW. 34 KT...150NE 150SE 120SW 130NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 03/1800Z 37.5N 55.0W MAX WIND 85 KT...GUSTS 105 KT. OUTLOOK VALID 04/1800Z 42.0N 48.5W MAX WIND 70 KT...GUSTS 85 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.2N 57.6W NEXT ADVISORY AT 30/0300Z $$ FORECASTER PASCH
Tags: number
sam
advisory
forecast
Tropical Storm Victor Forecast Discussion Number 2
2021-09-29 22:43:52| National Hurricane Center (Atlantic)
Issued at 800 PM CVT Wed Sep 29 2021 000 WTNT45 KNHC 292043 TCDAT5 Tropical Storm Victor Discussion Number 2 NWS National Hurricane Center Miami FL AL202021 800 PM CVT Wed Sep 29 2021 The cloud pattern continues to exhibit a large circulation with numerous curved bands surrounding the center. The strongest thunderstorms remain on the system's west side. The latest Dvorak estimates from TAFB and SAB have both increased to 2.5/35 kt, and on that basis, the cyclone has been upgraded to a 35-kt tropical storm. Victor is still on a west-northwest course at about 11 kt. There has been little change to the track forecast reasoning. The cyclone is expected to continue west-northwestward during the next couple of days as it remains steered by the flow on the south side of a deep-layer ridge. By late Friday, however, the models show the western periphery of the ridge being eroded due to a mid- to upper-level low over the subtropical central Atlantic. As a result, the cyclone should turn northwestward by Friday night and then northward late this weekend or early next week. There remains a fair amount of spread in the timing and location of the northward turn with the GFS and HWRF still on the right side of the guidance envelope and the ECMWF showing the slowest and westernmost solution. Overall, the consensus models have not changed much and neither has the official track forecast. The storm is expected to remain in conducive environmental conditions for strengthening during the next couple of days. During that time period, Victor is forecast to move over 28-29 deg C waters while embedded within a moist airmass with very low wind shear (less than 10 kt). Rapid intensification sometimes occurs when conditions are this favorable, however, since the storm is broad and does not yet have an inner core, gradual strengthening seems more reasonable. The NHC forecast brings Victor to hurricane intensity in 36 hours. In a few days, however, the models show a pronounced increase in southwesterly shear and a notably drier atmosphere. These unfavorable conditions should end the opportunity for strengthening and promote a weakening trend. The NHC intensity forecast is similar to the previous one and remains near a blend of the HCCA, IVCN, and IVDR consensus models. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 8.3N 25.5W 35 KT 40 MPH 12H 30/0600Z 8.8N 26.9W 45 KT 50 MPH 24H 30/1800Z 9.5N 28.9W 55 KT 65 MPH 36H 01/0600Z 10.3N 30.8W 65 KT 75 MPH 48H 01/1800Z 11.4N 32.4W 70 KT 80 MPH 60H 02/0600Z 12.8N 34.1W 70 KT 80 MPH 72H 02/1800Z 14.7N 35.8W 60 KT 70 MPH 96H 03/1800Z 19.3N 38.9W 50 KT 60 MPH 120H 04/1800Z 24.9N 40.9W 40 KT 45 MPH $$ Forecaster Cangialosi
Tags: number
discussion
storm
victor
Sites : [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] [52] [53] [54] [55] [56] [57] next »